Mechanism for varying the stroke of the keys of power-operated typewriters



May 12, 1959 E. FEss 'ETAL 2,886,153

MECHANISM FOR VARYING THE STROKE OF THE KEYS OF POWER-OPERATEDTYPEWRITERS Filed June 1. 1956 EM. F558 BRUNO A/lfSCf/AE United StatesPatent ()f'ice MECHANISM FOR VARYING THE STROKE on THE KEYS orPOWER-OPERATED TYPEWRITERS Emil Fess and Bruno Nitschke, Frankfurt amMain,

Application June 1, 1956, Serial No. 588,804

9 Claims. (Cl. 197-17) This invention relates to a device in apower-operated typewriter to set and adjust the operation of the keylevers of the keyboard.

More particularly this invention relates to a device or apparatus whichmay be provided as an attachment on or adjacent the key board of apower-driven typewriter Patented May 12, 1959 Fig. Zis a sectional viewtaken on the line 2-2 of Fig. 1 inthe direction of the arrows, and

Fig. 3 is a side elevation of a detail of the setting memher on anenlarged scale.

The key levers 1 are mounted on an axle or rod 2 in a known manner as isusual in typewriters. Each key lever 1 is provided with a rearwardlyextending or elongated part 3 with which it grips or contacts a pivotedrelease latch or pawl 5 rotatably mounted on a pin 4. The pawl 5 has aprojecting arm to contact and operate a swinging cam 7 mounted on a pin6. The cam 7 maybe brought into contact with a driving roller 8 to takewith it a driving lever 9 which latter, by means of a lever 10, willactuate its type lever 12 by means of a pull rod 11. An abutment trackor bar 14 is pivotally' mounted in a frame part 13 of the typewriter andthe key levers 1 and the like and it serves the purpose to render iteasier to operate the typewriting machine. In the usual not power-driventypewriters, which are in use at the present time, it is necessary topress down on each key of the key levers for an appropriate distance inorder that the particular type bars connected therewith are moved from atheir position of rest into their typing position.

Actually in power-driven typewriting machines it is only necessary topress on each key a very short distance since it is only necessary insuch power-driven typethe type bars a short distance until coupled tothe power- It has been determined in the past writers to move theparticular elements which operate ate a power-driven typewriter so thatthe operation of 1..

the machine will be;uniform and can be operated without diff culty. Suchdifiiculties in operation are essentially due to the fact that thepressure on the keys .of

v.the keyboard and their distance of movement suddenly changes from onetype of machine to another and it often happens that a beginner willinadvertently touch .the wrong key or keys and this will likewise causedifgficulties in operation.

a .It is therefore an object of the present invention to obviate thedifiiculties which are present in power-driven typewriters and this isaccomplished by changing the disment actuatable so that at first it willbe necessary to push down on the keys a greater distance, whichdistancecan be shortened after the operator becomes familiarwith theoperation of the machine.

After the operator is will contact the track bar 14 by means ofprojections or lugs 15 under the action of the springs 16 in theposition of rest of the key levers 1. The track bar 14 may be adjustedupwardly or downwardly by a lever 17 connected to a guide bar 18 and atransmission drive 19 by means of an eccentrically mounted shaft 20. Asshown in Fig. 2 the lugs 15 are provided at varying distances from thepivot axle 2 for the key levers 1 so that all the keys la will be liftedup or lowered the same distance when the bar 14 is adjusted up or down.

The adjustment of the lever 17 can be accomplished in many differentways.. In the illustrated structure the lever 17 is provided with aroller 24, Fig. 3, which, by means of a spring secured to the lever 17,will force the roller 24against a curved or cam member 23a of a settingmember 23. The setting member 23 is rotatable around a shaft or screwpin 22 and in order to adjust the lever 17 to different and definitepositions, the curved member 23a may be provided with grooves orcontours '25 into which the roller contacts. The different adjustedpositions may be indicated by numbers on the side of the. setting member23 as shown in Fig. 1.

The device or attachment operates as follows:

The ordinary operation of a power-driven typewriter of the type having acontinuously rotating operating roller for the type bars or type leversis in itself Well known. If now it should be desired to change thedistance necessary to press each key 1a downwardly to operate itsrespective type lever during typing, it is merely necessary to set thesetting member 23 to the desired position as governed by the numbersappearing thereon and which affords a visual indication of the 23, theresult is accomplished that the roller 24 on the lever 17 will beadjusted a certain distance from the fully acquainted With the use ofthe machine and par- -ticularly the operation of the keyboard, thedistance that each key lever is pushed down can be adjusted at will andto the desire of the operator. It is therefore a still further objectIofiithe invention" to provide apower-driven typewriter with means toset the distance that each key must be pressed insofar as the entirekeyboard is con- ;cerned and'such distance can be regulated at will.

f Anothenobjectof the invention resides in the, pro- 'visionof means ina power-driventypewriter to change shaft for pin 22 as governed by thecam 23a. Thus. the

lever 17 will be accordingly adjusted and by means of the guide bar 18and the transmission drive 19, the cocentric shaft 20 will be rotated toa certain position. Thus upon rotation of the eccentric shaft 20, thetrack or bar 14, which is actually an abutment, will be moved or swungaround its axis or shaft 21, Fig. 2. Since the key levers 1 are eachunder the influence of its respective spring 16, each lever will contactor abut against the track 14 by means of the corresponding projectingmember 15 and thus all of the key levers will be adjusted accordinglyand as a unitso that the type bars willall be raised or. lowereddepending upon the direction of adjustment desired. After adjustment allof the key i i R 2,886,158

, 3 ings shows in dotted lines, for example, an adjustment of thekey'levers from the full line position.

It is of course not necessary that the structure according to thisinvention shall be used. as an attachment since it is obvious that eachnew machine can be built with the adjusting mechanism permanentlyinstalled and ready to function at any time. The adjusting mechanism isparticularly useful when during typing it is desired to change theamount of movement of each type key downwardly, that is, the free playfrom the top position of rest until the lower position is reached wherethe revolving cylind'er takes hold to actuate the respective type bar.This distance can be adjusted to the exact amount to suit the comfortand typing speed of the typist.

We claim as our invention:

1. A device for adjusting the downward movement of the key lovers of apower-driven typewriter with type bars, comprising an abutment barpivotally mounted to be raised and lowered relative to the key leverswhich latter abut against the bar in the position of rest of the keylevers, a setting member rotatably mounted on the typewriter, and meansconnected to the setting member and the abutment bar so that upon arotary movement of the setting member the abutment bar will be adjustedrelative to the key levers to adjust the downward movement of the keylevers as a free play before the type bars are driven to printingposition, said means including an eccentric shaft extending over and incontact with the abutment bar and which is" connected to be adjusted bythe setting member.

2. A device for adjusting the downward movement of the key levers of apower-driven typewriter with type bars, comprising an abutment barpivotally mounted to be raised and lowered relative to the key leverswhich latter abut against the bar in the position of rest of the keylevers, a setting member rotatably mounted on the typewriter, and meansconnected to the setting member and the abutment bar so that upon arotary movement of the setting member the abutment bar will be adjustedrelative to the key levers to adjust the downward movement of'thekeylevers as a free play before the type bars are driven to printingposition, said means including an eccentric shaft extending over and incontact with the abutment bar and which is connected to be adjusted bythe setting member and the setting member having a cam surface of aconfiguration to define adjustment positions for the abutment bar.

3. In a power-driven typewriter, an attachment on the frame of thetypewriter and the keyboard levers comprising a setting member rotatablymounted on the frame, an abutment bar for limiting the upward travel ofall the key levers, and means connected to the setting member and theabutment bar to adjust the latter to the desired distance of movement ofthe key levers, said means including a cam on the setting member and aneccentric shaft contacting the abutment bar with interconnectingelements between the cam and the shaft to operatively set the latter.

4. In a power-operated typewriter having rows of keys on key leversmounted pivotally about an axis, a bar above the key levers mounted tobe raised and lowered and forming an abutment for the key levers intheir position of rest, a setting member, means connected to the settingmember and the bar for adjusting the bar by said setting member, andcontacting means between the key levers and the bar and arranged to varythe stroke of all rows of keysa uniform" distance by said settingmember.

5. In a power-operated typewriter having rows of keys on key leversmounted pivotally about an axis,a bar above the key levers mounted toberaised andlowered and forming an abutment for the key levers in theirposition of rest, a setting member, means connected to the settingmember and the bar for adjusting the bar by said setting member, andcontacting means between the key levers and the bar and comprising lugson the key levers arranged at diiferent distances from the axis of thekey levers associated with different rows of keys to vary the stroke ofall rows of keys a uniform distance by said setting member.

6. In a power-operated typewriter having rows of keys on key leversmounted pivotally about an axis, a bar above the key levers pivotallymounted to be raised and lowered and forming an abutment for the keylovers in their position of rest, a setting member, means connected tothe setting member and the bar for adjusting the bar by said settingmember, and contacting means between the key levers and the bar andcomprising contacting points on the bar arranged at diiferent distancesfrom the axis of the bar for the key levers associated with differentrows of keys to vary the stroke of all rows of keys a uniform distanceby said setting member.

7. In a power-operated typewriter having rows of keys on key leversmounted pivotally about an axis with type bars, a bar above the keylevers mounted tobe raised and lowered and forming an abutment for thekey levers in their position of rest, a setting member mounted on thetypewriter, and means connected to the setting member and the bar sothat upon a movement of the setting member the abutment bar will beadjusted to vary the stroke of the keys as a free play before thetypebars are driven to printing position, said means including an eccentricshaft extending over and in contact with the abutment bar and which isconnected to be adjusted by the setting member,

8. In a power-operated typewriter having rows of keys on key leversmounted pivotally about an axis with type bars, a bar above the keylevers mounted to be raised and lowered and forming an abutment for thekey levers in their position of rest, a setting member rotatably mountedon the typewriter, and means connected to the setting member and the barso that upon a rotary movement of the setting member the abutment barwill be adjusted to vary the stroke of the keys as a free play beforethe type bars are driven to printing position, said means including aneccentric shaft extending over and in contact with the abutment bar andwhich is connected to be adjusted by the setting member, and the settingmember having a cam surface of a configuration to define adjustmentpositions for the abutment bar.

9. In a power-actuated typewriter, an attachment on the frame of thetypewriter for adjusting the operation of the keys of the keyboardcomprising a setting member rotatably mounted on the frame, an abutmentbar for limiting the upward travel of the key levers, and meansconnected to the setting member and the abutment bar to adjust thelatter to the desired length of stroke of the keys, said means includinga cam on the setting member and an eccentric shaft contacting theabutment bar with interconnecting elements between the cam and the shaftto operatively set the latter.

References Cited in the file of this patent UNITED STATES PATENTS2,020,223 Utz NOV. 5, 1935 2,087,409 Koca July 20, 1937 2,682,944Schremp July 6, 1954 yaw-Mi

